﻿/*
 * Copyright (c) 2015-2016 Constantijn Evenhuis (blueprints@const.nl)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
using Blueprints.IO;
using System;

namespace Blueprints.Editing.Actions
{
    internal sealed class ChangeValueAction : IUndoableAction
    {
        public ChangeValueAction(EditNode node, string value)
        {
            Node = node;
            Subject = node.GetParentNode() ?? node;

            int nodeIndex = node.EditContext.Nodes.IndexOfContentNode(node);
            if (nodeIndex < 0)
            {
                BeforeValue = null;
            }
            else
            {
                BeforeValue = node.EditContext.Nodes[nodeIndex].TraceableNode.Content;
            }

            AfterValue = value;
        }

        public EditNode Node
        {
            get;
            private set;
        }

        public EditNode Subject
        {
            get;
            private set;
        }

        public string BeforeValue
        {
            get;
            private set;
        }

        public string AfterValue
        {
            get;
            private set;
        }

        public EditNode Do()
        {
            int nodeIndex = Node.EditContext.Nodes.IndexOf(Node);
            if (nodeIndex < 0)
            {
                throw new InvalidOperationException();
            }

            int contentIndex = Node.EditContext.Nodes.IndexOfContentNode(nodeIndex);
            if (contentIndex < 0)
            {
                if (AfterValue != null)
                {
                    Node.EditContext.Nodes.Insert(nodeIndex + 1, new EditNode(Node.EditContext, new ContentNode(AfterValue)));
                }
            }
            else
            {
                if (AfterValue != null)
                {
                    Node.EditContext.Nodes[contentIndex].TraceableNode.Content = AfterValue;
                }
                else
                {
                    Node.EditContext.Nodes.RemoveAt(contentIndex);
                }
            }

            return Subject;
        }

        public EditNode Undo()
        {
            int nodeIndex = Node.EditContext.Nodes.IndexOf(Node);
            if (nodeIndex < 0)
            {
                throw new InvalidOperationException();
            }

            int contentIndex = Node.EditContext.Nodes.IndexOfContentNode(nodeIndex);
            if (contentIndex < 0)
            {
                if (BeforeValue != null)
                {
                    Node.EditContext.Nodes.Insert(nodeIndex + 1, new EditNode(Node.EditContext, new ContentNode(BeforeValue)));
                }
            }
            else
            {
                if (BeforeValue != null)
                {
                    Node.EditContext.Nodes[contentIndex].TraceableNode.Content = BeforeValue;
                }
                else
                {
                    Node.EditContext.Nodes.RemoveAt(contentIndex);
                }
            }

            return Subject;
        }
    }
}
